Yes, I checked the item type that is binding in the event, you can see the condition if in my code.
You can create a sample webpart and copy the code example above then you will see the repeater_ItemDataBound fired 2 times insteads of run through the item of repeater.
Pleae notice that it not happen if you bind the datasource at page_load event. It happen only when we bind the datasource at OnContentLoaded event.
I'm using KenticoCMS7.